Antenna Designs

Antenna design is one of the most popular applications for the EM simulation tools. It is still challenging problem since the shape and size of the antenna can vary dramatically depends on the resonating frequency, gain and the bandwidth. Traditional challenges also include applying a perfect absorbing boundary condition in order to model an open-bounded problem for the finite domain in the differential simulator. Wavenology EM can be used for the design of many kinds of antenna components, including microstrip, horn, helical and arrayed antennas. The post-processing facilities of Wavenology EM yield many aspects of interest for an antenna designer, with nearfield plots, directivity or farfield gain in both time and frequency domains for single antennas or arrays in 3D. Several typical examples simulated by Wavenology EM are listed in the following:


 

Yagi-Uda Antenna

 
The Yagi Antenna is one of the most widely applied antennas that can be found on the roof of buildings as you look around the street. It is easy to construct and has a high gain. The Yagi antennas typically operate in the HF to UHF bands (about 3 MHz to 3 GHz).

 




 

Spiral Antenna

 
Spiral antennas’ feature is wide band. The fractional bandwidth can be as high as around 20:1. Spiral antennas typically have a radiation peak directed perpendicular to the plane of the spiral. Such type of antenna is widely used in the cases where wideband antennas that do not occupy much space are needed. The following is a Wavenology EM simulated example

 





 

Patch Antenna

 
Patch antenna is usually fabricated by mounting a shaped metal sheet on a mother-substrate, such as a printed circuit board, with a grounded layer bonded to the other side of the substrate. Common microstrip antenna shapes are square, rectangular, circular and elliptical. However the shape is not restricted. Any continuous shape is feasible. The following lists two Wavenology EM simulated examples.

 





 

Vivaldi UWB 7:1

 





 

Dish Antenna

 
A dish antenna uses a concaved open surface to reflect and guide the radio waves. The major feature of a dish antenna is that it is highly directive and hence can achieve very high gain. Such antennas are widely used for point-to-point communications, such as satellite and spacecraft communication antennas or radar systems. The following shows a Wavenology EM simulated example.

 




 

Helical Antenna

 
A helical antenna is fabricated by wrenching a conducting wire into a helix shape around a supporting pillar. In most cases, the antenna is mounted on a ground plane. The feature of helical antennas is that it can operate two principal modes: normal mode or axial mode. As shown in the following example simulated by Wavenology EM.

 




 

Cavity-Backed Slot Antenna

 
Cavity-backed slot antenna is using the resonance of EM waves in a slot to radiate the EM energy. The designs of the slot shapes can be various.

 




 

Slotted Waveguide Antenna

 
Slotted antenna arrays carved on waveguides are a popular antenna in navigation, radar and other radio-frequency systems. They are simple to fabricate, and radiate with high efficiency. A Wavenology EM simulated example of a slotted waveguide array is shown below:

 




 

Horn Antenna

 
Horn antenna consists of a waveguide feeding part and a horn shaped radiating part. Horns are widely used above 300 MHz.

 





 

Dual-Band Printed Electrically Small Antenna

 
This example provides a dual-band compact ESA unit suitable for the MIMO application in smart and portable wireless devices. The following presents the configuration of the dual-band electrically small antenna with two capacitive split-ring resonators (SRR). This ESA structure is fed by a high performance 50 Ω coaxial RF sub-Miniature version B connector. The inner conductor of this connector is connected to the right strip of the loop and the outer pins of the connector are directly soldered to the left strip of the loop. The ESA operates at dual frequency bands. The fundamental idea is that two resonant modes are achieved through the field interaction among SRRs and the small loop. In this interaction, two capacitive SRRs play the role of impedance matching to the small loop.

 




 

Antenna Arrays

 
Antenna array is a group of radiating elements. By controlling the phases and amplitudes of the radiators, the flexibility of operating the antenna is dramatically increased. The following is 16*16 antenna arrays simulated by Wavenology EM.